Yes, but with some restrictions.
The BACnet discovery uses two services – called ‘Who-Is’ and ‘I-Am’ these messages rely on the use of broadcasts. Without the ability to send broadcast messages on a network, CAS BACnet Explorer will not be able to do the initial discovery of objects.
Once a device or objects has been added to CAS BACnet Explorer it no longer uses broadcasts messages to communicate with it. You should be able to poll a device for its object list and read/write its objects properties.
You can add BACnet objects and devices to CAS BACnet Explorer manually from the discover dialog. You will need to know some of the devices settings. Network type, IP/MAC address, network, Device instance, Object type, Object identifier.